Where does Illinois Republican Sen. Mark S. Kirk start in his bid for re-election? It depends on whom you ask.

The Rothenberg & Gonzales Political Report/Roll Call currently rates the 2016 race as a Tossup, while the Cook Political Report says it is a "Lean Republican" contest. The folks in the statistical wing of the handicapping world are invisible, because the race hasn’t formed and there are no meaningful polls. My own view is that Kirk has a significantly uphill fight for a second term. I regard him as an underdog.

Kirk certainly has a chance to win re-election, but the state’s fundamentals are so difficult for any Republican — even one with his appeal — that he is less than even money to win in 2016. Of course, my assessment could be different a year from now.

Apart from his Republican affiliation, Kirk’s profile isn’t a problem.

He graduated with honors from Cornell University, holds a master’s degree from the London School of Economics and earned a law degree from Georgetown. A 24-year veteran of the Navy Reserves, Kirk was a staffer on Capitol Hill and spent two years at the State Department. He was elected to a swing House district north of Chicago in 2000 and was re-elected five times, including in 2006 and 2008, two brutal elections for Republicans.

His record was generally that of a moderate conservative, more to the right on economic and foreign policy matters and more to the center on social issues.

Here is how CQ’s "Politics in America" began its 2010 profile of the Illinois Republican:

“Kirk, one of a dwindling number of Republican House moderates, works to meet the concerns of his centrist-minded district in the Chicago suburbs by pushing for fiscal restraint while backing such liberal social measures as gun control, embryonic stem cell research and increases in the minimum wage. Democratic leaders often look to him for support, and he reaches out to like-minded conservatives in their party.”

That positioning was ideal in an upscale district that ranked first in the state in the 2000 census for the percentage of residents with a college education, as well as for those with white-collar jobs. The district ranked a very close second in median income ($71,663, compared to $46,590 statewide).

The Republican’s strong support for Israel was also an asset, given the substantial Jewish population in the district.

Kirk won an open Senate seat in 2010, and he almost certainly was the only Illinois Republican who could have done so — even in the national GOP electoral wave. He defeated Illinois state Treasurer Alexi Giannoulias in November by a mere 59,220 votes (out of more than 3.7 million cast), for a narrow 48 percent to 46.4 percent victory.

Giannoulias, who won his treasurer’s election in 2006 with a boost from then-Sen. Barack Obama, turned out to be a flawed candidate. He was 34 years old and seemed like an overly ambitious empty suit to many observers. Kirk outraised him, $14.3 million to about $10 million.

During the campaign, the Democrat was hounded by problems at the Broadway Bank, which his father founded and where he worked for a time. The state seized the bank seven months before the Senate election, and Giannoulias was constantly on the defensive about the bank’s bad loans to a number of unsavory characters.

The problem for Kirk is that his electoral problems multiply exponentially in any kind of “normal” year.

Republicans have won only two of the past dozen Illinois Senate elections. The only other victorious Republican, Peter Fitzgerald, narrowly defeated a severely damaged Democratic incumbent, Carol Moseley Braun, but did not seek re-election. The last GOP senator in Illinois to win re-election was Charles Percy, who won a third term in 1978, but lost his bid for a fourth in 1984.

Republicans have won gubernatorial races in the state, and the sitting GOP governor was just elected in 2014 after years of Democratic mismanagement. But as I have written often, federal offices are different (and inherently more ideological) than contests for state office. Higher turnout presidential cycles, such as 2016, are particularly challenging for Republican candidates in reliably Democratic states such as Illinois.

A serious stroke in January 2012 threatened Kirk’s life and career, but he has fought back and insists he will seek re-election . It’s not entirely clear how his medical history and current condition will affect that bid.

It’s also unclear how a potential primary from the right could affect the senator. It could force him to emphasize his conservative credentials, thereby giving ammunition to his Democratic opponent in November. Or, it could add to his reputation as a moderate for the general election. Former GOP Rep. Joe Walsh, a one-term favorite of the tea party, has expressed interest in challenging Kirk.

Obviously, even with the state’s partisan bent, Democrats must nominate a serious opponent to defeat Kirk. A number of members of Congress have been mentioned, with most of the talk centering on Rep. Tammy Duckworth, a Democrat who lost both legs while fighting in Iraq. She would be a formidable challenger.

It’s too soon to bury Kirk politically. He has shown plenty of courage, both personally and politically.

But the fundamentals — and the odds — are against him in the Democratic bastion of Illinois. I simply don’t buy the idea that he starts off as even money in the race, let alone that the seat leans Republican.